### 2.8.6 Simplification of a pair of integers : `simp2`

`simp2` takes as argument two integers or a list of two integers
which represent a fraction (for two polynomals see 2.28.6).

`simp2` returns the list of the numerator and the denominator of
an irreducible representant of this fraction
(i.e. after simplification).

Input :

`simp2(18,15) `

Output :

`[6,5]`

Input :

`simp2([42,12])`

Output :

`[7,2]`